#include <stdio.h>
#include <stdlib.h>
#include <math.h>

int main()
{
    int note1,note2;
    double f,p;

while (true) {
    printf("Please enter first MIDI note (0-127): ");
    scanf("%d", &note1);
    int valid = checkIfValid(note1);
    if (valid == 1)
        break;
    else
        printf("NO");
}

while (true) {
    printf("Please enter second MIDI note (0-127): ");
    scanf("%d", &note2);
    int valid = checkIfValid(note1);
    if (valid == 1)
        break;
    else
        printf("NO");
}

    return 0;
}

int checkIfValid(int note) {
    if (note >= 0 && note <= 128)
        return 1;
    else
        return 0;
}